The public service has been given the green light to hire more than 50 senior bureaucrats on annual salaries of up to $366,000 since the Abbott Government imposed its hiring clampdown last year, a Senate Estimates committee has been told.

Permission was also given by the Public Service Commission for departments and agencies to hire 430 non-executive public servants since October, in the same period that has seen hundreds of redundancies from the service.

The high-level hirings come despite the departures of 74 of the bureaucracy's elite "senior executive service" since July 2013, many of whom took generous "incentives to retire" packages.